Aims: Aortic structural and hemodynamic alterations have deleterious effects on the left ventricle (LV). Our aims were to: 1) design indices of as-cending aorta (AA) flow from MRI data and 2) assess changes in such indices in dilated (DCM) and hypertrophic (HCM) cardiomyopathies.

Methods: We studied 17 DCM (53±11years) and 15 HCM patients (56±16years) matched for age with 34 controls (53±10years). MRI AA through-plane velocities were automatically segmented to estimate flow curves throughout the cardiac cycle. Then, indices reflecting flow curves changes during the late systolic deceleration time interval (DT) were derived: a) T_1/2: the time interval required for flow deceleration to reach half of its systolic peak, in percentage of DT, and b) DR_1/2: the decrease in flow during half of DT, in percentage of systolic peak.

Results: T_1/2 was 56.3±6.6% and DR_1/2 was 43.5±6.5% in controls. AA flow waveform during late-systole changes significantly in cardiomyopathies. Indeed, while it tends to be steeper in HCM as reflected by significant (p<0.001) decrease in T_1/2 (43.1±17.3%) and increase in DR_1/2 (54.9±16.1%), it tends to be flat in DCM as reflected by significant (p<0.001) increase in T_1/2 (68.2±6.7%) and decrease in DR_1/2 (31.6±7.8%). Furthermore, such differences remained significant while accounting for gender, BMI and heart-rate (MANOVA).

Conclusion: We found significant changes in AA flow patterns in the presence of cardiomyopathies, reflecting changes in both LV contractile capacity and aortic cushioning. Such aortic indices might be of major usefulness in pathologies associating aortic stiffening with LV hypertrophy such as hypertension.